Among pesticides, formulations such as emulsifiable concentrates, wettable powders and flowables are intended for dilution with water for use as spray applications. Among such formulations, emulsifiable concentrates involve problems of, e.g., toxicity, irritation, flammability and bad odor because they use an organic solvent as a carrier. Likewise, due to their fine powder form, wettable powders are inconvenience in metering and are likely to affect the safety of operators because they are blown up into the air (in a process known as “dustiness”) when prepared into a spray solution.
Furthermore, flowables take the form of suspension and hence overcome the problems of metering and dustiness associated with wettable powders. However, such flowable formulations are highly viscous and difficult to remove from containers, so a small portion of the formulations will remain in the containers and cause problems in disposal of the containers. To overcome the above problems, recent attempts have been made with particular regard to the granulation of wettable powders. Namely, the granulation of wettable powders allows improvements in dustiness and metering of wettable powders.
However, if conventional binders for granules are used to overcome the problem of dustiness, harder granules may generally be produced and be responsible for insufficient efficacy due to reduced dispersion in water, etc. In contrast, if an attempt is made to provide the same degree of dispersion in water as observed in wettable powders, problems of low hardness and easy powdering of granules will arise. As a result, the formulations contain more products in fine powder form and are more likely, during spraying, to cause inhalation of the fine powder products by operators and to cause powder scattering outside a target area to be sprayed, thus leading to the same problems caused when using traditional wettable powders. Although various attempts have been made to use conventional binders for granulated wettable powders, the use of such binders could not simultaneously achieve both improved powdering property and good dispersion in water.
To solve these problems, many studies have been conducted on the granulation of wettable powders. Granulated wettable powders known from these studies include:
a granulated pesticidal wettable powder comprising a pesticidal active ingredient in combination with starch and a water-soluble inorganic salt such as ammonium sulfate (JP 51-1649 A);
a water-dispersible granule capable of forming a good suspension, which comprises a plant protection agent and a specific solid wetting agent and/or an ammonium salt (JP 3-193702 A);
a water-soluble pesticidal granule comprising a water-soluble pesticidal active ingredient, lactose and a surfactant as essential ingredients (JP 6-92803 A); and
a granulated wettable powder prepared by extrusion granulation of a novel composition comprising a pesticidal active ingredient and diatomaceous earth, and preferably further comprising a surfactant (JP 6-128102 A).
Likewise, solid formulations based on starch hydrolysate include:
a powdered pesticidal composition prepared by adsorbing a pesticidal active ingredient and a surfactant onto drum-dried powder of an aqueous dispersion comprising starch hydrolysate and one or more polymer materials selected from the group consisting of seaweed extract, plant seed mucilage, plant fruit mucilage, plant resinoid mucilage, microorganism-produced mucilage, water-soluble or water-dispersible proteins, cellulose derivatives and water-soluble synthetic polymers (JP 60-36402 A); and
a pesticidal solid emulsion comprising a spray-dried product of an aqueous emulsion containing, as essential ingredients, a pesticidal active ingredient with a melting point of 70° C. or less, a surfactant, dextrin and/or lactose, and water (JP 3-47103 A).
Granulated pesticidal compositions incorporated with sodium lignosulfonate include:
a water-dispersible granulated pesticidal composition characterized by containing two types of surfactants, one of which is selected from lignosulfonate, a naphthalenesulfonate formaldehyde condensate and the like, and the other of which is selected from an alkylnaphthalenesulfonate, a polyoxyethylene alkylphenyl ether sulfate and the like (JP 5-43402 A);
a pesticidal composition comprising 5-ethyl-5,8-dihydro-8-oxo-1,3-dioxolo[4,5-g]quinoline-7-carboxylic acid (oxolinic acid) and N-propyl-N-[2-(2,4,6-trichlorophenoxy) ethyl]imidazole-1-carboxamide (prochloraz) dissolved in a hydrophobic organic solvent, wherein these two ingredients are dispersed or emulsified into water containing a lignosulfonate surfactant with a degree of sulfonation of 2.5 or less (JP 7-17810 A);
a (granulated) wettable powder comprising one or more pesticidal active ingredients and a highly-purified and partially-desulfonated lignosulfonate salt (JP 8-34702 A); and
a granulated wettable powder comprising a pesticidal active ingredient, a lignosulfonate salt, a polyoxyethylene alkyl ether sulfate salt and a water-soluble inorganic salt (JP 2002-179506 A).
However, there is no disclosure on a composition comprising a sulfate or phosphate salt of a polyoxyalkylene arylphenyl ether in combination with highly sulfonated sodium lignosulfonate.